Processes for the preparation of polymers of itaconic acid are known in the art. However, while the prior art processes have had some impact on resolving inherent difficulties in polymerizing this dicarboxylic acid, low polymerization conversion of the acid continues to be a problem. High levels of unpolymerized monomers in the final product raise serious environmental concerns and cause significant application problems. Additionally, many of the processes are known to be difficult, erratic and inconsistent.
European Patent Application 0 506 246 published Sep. 30, 1992 describes a process for preparing polymers of itaconic acid, optionally together with acrylic acid, in water wherein the monomers(s) are neutralized to a level of 80 to 100 equivalent percent prior to or during the polymerization reaction.
The method described in the latter application has however, not been found useful in the polymerization of itaconic acid with vinyl acetate or vinyl alcohol due to poor conversion of both itaconic acid and the vinyl compound.